text: /**
   * Copyright (c) 2018 - 2020, Nordic Semiconductor ASA
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
   *    such product, must reproduce the above copyright notice, this list of
   *    conditions and the following disclaimer in the documentation and/or other
   *    materials provided with the distribution.
   *
   * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
   *    contributors may be used to endorse or promote products derived from this
   *    software without specific prior written permission.
   *
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
   *
   * 5. Any software provided in binary form under this license must not be reverse
   *    engineered, decompiled, modified and/or disassembled.
   *
   * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
   * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
   * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #include "sdk_config.h"
  #include "nordic_common.h"
  
  #if NRF_MODULE_ENABLED(NRF_CRYPTO) && \
      NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_OBERON) && \
      NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_OBERON_ECC_SECP256R1)
  
  #include <stdint.h>
  #include <stdbool.h>
  #include <string.h>
  
  #include "nrf_crypto_ecc.h"
  #include "nrf_crypto_rng.h"
  #include "nrf_crypto_ecdsa.h"
  #include "oberon_backend_eddsa.h"
  #include "nrf_crypto_eddsa_shared.h"
  #include "ocrypto_ecdsa_p256.h"
  
  
  #define OBERON_HASH_SIZE_FOR_SECP256R1 (256 / 8)
  
  
  ret_code_t nrf_crypto_backend_secp256r1_sign(
      void          * p_context,
      void    const * p_private_key,
      uint8_t const * p_data,
      size_t          data_size,
      uint8_t       * p_signature)
  {
      int     result;
      uint8_t session_key[32];
  
      nrf_crypto_backend_secp256r1_private_key_t const * p_prv =
          (nrf_crypto_backend_secp256r1_private_key_t const *)p_private_key;
  
      if (data_size < OBERON_HASH_SIZE_FOR_SECP256R1)
      {
          return NRF_ERROR_CRYPTO_INPUT_LENGTH;
      }
  
      result = nrf_crypto_backend_oberon_ecc_secp256r1_rng(session_key);
      if (result != NRF_SUCCESS)
      {
          return result;
      }
  
      result = ocrypto_ecdsa_p256_sign_hash(p_signature, p_data, p_prv->key, session_key);
  
      return result == 0 ? NRF_SUCCESS : NRF_ERROR_CRYPTO_INTERNAL;
  }
  
  
  ret_code_t nrf_crypto_backend_secp256r1_verify(
      void          * p_context,
      void    const * p_public_key,
      uint8_t const * p_data,
      size_t          data_size,
      uint8_t const * p_signature)
  {
      int result;
  
      nrf_crypto_backend_secp256r1_public_key_t const * p_pub =
          (nrf_crypto_backend_secp256r1_public_key_t const *)p_public_key;
  
      if (data_size < OBERON_HASH_SIZE_FOR_SECP256R1)
      {
          return NRF_ERROR_CRYPTO_INPUT_LENGTH;
      }
  
      result = ocrypto_ecdsa_p256_verify_hash(p_signature, p_data, p_pub->key);
  
      if (result != 0)
      {
          return NRF_ERROR_CRYPTO_ECDSA_INVALID_SIGNATURE;
      }
      return NRF_SUCCESS;
  }
  
  
  #endif // NRF_MODULE_ENABLED(NRF_CRYPTO) && NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_OBERON) && NRF_MODULE_ENABLED(NRF_CRYPTO_BACKEND_OBERON_ECC_SECP256R1)
  